Add Mutable type

[kainiedziela]

Fixes #146

SetMutable

Creates a type that converts the given keys from readonly to mutable. The remaining keys are kept as is.

Use-case: You want to define a single model where the only thing that changes is whether or not some of the keys are mutable.

import {SetMutable} from 'type-fest';

type Foo = {
	readonly a: number;
	b: string;
	readonly c: boolean;
}

type SomeMutable = SetMutable<Foo, 'b' | 'c'>;
// type SomeMutable = {
// 	readonly a: number;
// 	b: string; // Was already mutable and still is.
// 	c: boolean; // Is now mutable.
// }

[papb]

Hello, nice work, is there a plan to create SetReadonly as well?

[sindresorhus]

Hello, nice work, is there a plan to create SetReadonly as well?

Sure. Open an issue or PR about it.

[voxpelli]

Sorry for not reviewing earlier, I had my notifications for this repo setup in a way that made me miss the request for reviews.

My "request changes" isn't for all of my comments, but mostly for things like the erroneous comments in the test file.

As a new co-maintainer on this repo I'm still figuring out some things myself.

[voxpelli]

Wow, you're fast, I only had time to review #153 and then I'm back to this one 😅

Well, here's some follow up thoughts

[papb]

What do you think of also making Mutable<readonly [string, number] return [string, number]? I needed this recently and had to write my own.

[kainiedziela]

What do you think of also making Mutable<readonly [string, number] return [string, number]? I needed this recently and had to write my own.

This sounds useful to me. @sindresorhus thoughts?

[voxpelli]

I think we should open a separate issue / PR for accepting arrays into Mutable, to keep this PR as focused as possible so we can get it reviewed and merged without too much effort 😉

Sorry for lagging with my re-review, I’m a bit behind at work right now.

[sindresorhus]

I think we should open a separate issue / PR for accepting arrays into Mutable, to keep this PR as focused as possible so we can get it reviewed and merged without too much effort 😉

Agreed: #176

[sindresorhus]

@voxpelli LGTY?

[sindresorhus]

Actually, I missed that the tests are failing. You need to fix those.

[voxpelli]

LGTM 👍

[voxpelli]

@sindresorhus Do you want me to merge?

[sindresorhus]

Sure, go ahead.